diff --git a/problems/kamacoder/0044.开发商购买土地.md b/problems/kamacoder/0044.开发商购买土地.md
index 739e2cad..efad56da 100644
--- a/problems/kamacoder/0044.开发商购买土地.md
+++ b/problems/kamacoder/0044.开发商购买土地.md
@@ -212,13 +212,14 @@ public class Main {
         int horizontalCut = 0;
         for (int i = 0; i < n; i++) {
             horizontalCut += horizontal[i];
-            result = Math.min(result, Math.abs(sum - 2 * horizontalCut));
+            result = Math.min(result, Math.abs((sum - horizontalCut) - horizontalCut));
+            // 更新result。其中，horizontalCut表示前i行的和，sum - horizontalCut表示剩下的和，作差、取绝对值，得到题目需要的“A和B各自的子区域内的土地总价值之差”。下同。
         }
 
         int verticalCut = 0;
         for (int j = 0; j < m; j++) {
             verticalCut += vertical[j];
-            result = Math.min(result, Math.abs(sum - 2 * verticalCut));
+            result = Math.min(result, Math.abs((sum - verticalCut) - verticalCut));
         }
 
         System.out.println(result);